mTypewriter was one of the very first apps I bought for my iPad (insert pause to wipe away a nostalgic tear) and I still keep it on my iPad as a "show-off" app. Yes, there are other apps which are FAR more impressive in many ways, but I still find that for those who are unfamiliar with the iPad, this app is one of the most effective, entertaining and immediate accessible.
Unlike other apps, it's not a program that you might also find on a laptop computer. It demonstrates several advantages of the iPad (portability, touchscreen, etc.) with humor. Plus it has never, ever crashed on me.
Anyway, it's been updated! Now you can show off your digital manual typewriter with red AND black ink as well as better document management.